The general objective of this proposed core program project is to initiate broad, interdisciplinary experimental and clinical studies in the area of communicative disorders. In the field of ear research, our specific objectives are directed towards four major problems: 1) presbycusis, 2) cellular preservation, 3) ototoxicity and 4) residual function after trauma. In the field of laryngeal research, our specific objectives are: 1) neonatal tolerance and antigenic maturation, 2) canine immune responses and 3) mammalian nucleated cell membranes. Approaches to be employed in the study of these problems include the following disciplines: anatomy, chemistry, pharmacology, physiology, microbiology, psychoacoustics and clinical diagnostic tools.